Losing network connection on Raspberry Pi

I recently installed HomeAssistant on a Raspberry PI 3 B+ using an external USB SSD for storage and after only half a day to a day, I am unable to access the UI via the network. When I look at the LAN port on the back of the Pi, there are no activity lights which makes me think the network card/port has somehow been disabled.

As I am new to HomeAssistant I have tried completely rebuilding several times and the same thing happens every time. I have also tried physically rebooting the Pi, but with no effect. The network connection does not come back up.

I have not been able to find any other posts with this specific issue so I’m hoping someone can point me in the right direction to troubleshoot.